Measuring apparatus for detecting distance between vehicles and related warning system

Abstract

A measuring apparatus for measuring an actual distance between vehicles and comparing the measured distance with a reference distance. The reference distance (SL) is obtained on the basis of: a personal space (VR·TIMEK) being an uneasy distance peculiar to a driver and obtained in accordance with the own vehicle speed; a free running distance (VRR·TIMEN) corresponding to a response time of a driver's braking operation and a relative speed between two vehicles; a braking distance (VRR 2 /(2·GR)) corresponding to a depressing strength of a braking pedal in the driver's braking operation and the relative speed; and an acceleration change distance (αG·GA) corresponding to a relative acceleration between the two vehicles, using the following equation: SL=VR·TIMEK-VRR·TIMEN+VRR.sup.2 /(2·GR)-αG·GA where VR represents the own vehicle speed, TIMEK represents an uneasy factor, VRR represents the relative speed, TIMEN represents a response factor of the driver's braking operation, GR represents a braking deceleration factor, αG represents a preceding vehicle acceleration, and GA represents a preceding vehicle deceleration factor.

What is claimed is: 
     
       1. A measuring apparatus comprising: measuring means for measuring an actual distance between a vehicle and an object positioned in front of said vehicle;   calculating means for calculating a reference distance between said vehicle and said object based on traveling conditions of said vehicle and said object, respectively; and   judging means for judging whether said actual distance measured by said measuring means is less than said reference distance calculated by said calculating means,   wherein said calculating means comprises: first means for determining a personal space for a given driver in accordance with a speed of said vehicle, said personal space being defined as a subjectively determined distance between said vehicle and said object at which said given driver is brought into a state of uneasiness;   second means for obtaining a free running distance, said free running distance representing a distance that said vehicle travels until a vehicle braking operation is effected; and   third means for obtaining a braking distance, said braking distance representing a distance that said vehicle travels until said vehicle is stopped, after said vehicle braking operation is effected,     wherein said calculating means calculates said reference distance based on said personal space obtained by said first means, said free running distance obtained by said second means, and said braking distance obtained by said third means, and wherein said calculating means calculates said reference distance using the formula:   VR·TIMEK-VRR·TIMEN+VRR.sup.2 /(2·GR)        where VR represents said speed of said vehicle, TIMEK represents an uneasy factor expressed in terms of time and corresponding to said personal space, VRR represents a relative speed between said vehicle and said object, TIMEN represents a response factor corresponding to a response time for actuating said vehicle braking operation, and GR represents a braking deceleration factor corresponding to a depressing strength of a braking pedal in said vehicle braking operation.   
     
     
       2. The measuring apparatus in accordance with claim 1, wherein said personal space, said free running distance, and said braking distance are determined based on experiential data collected from a given driver's driving habits. 
     
     
       3. The measuring apparatus in accordance with claim 1, wherein said respective travelling conditions of said vehicle and said object are measured as experiential data in relation to braking conditions of said vehicle, wherein said reference distance is corrected based on said experiential data. 
     
     
       4. The measuring apparatus in accordance with claim 1, wherein said reference distance is manually adjustable. 
     
     
       5. The measuring apparatus in accordance with claim 1, wherein said TIMEK, TIMEN and GR are variable to adjust said reference distance. 
     
     
       6. The measuring apparatus in accordance with claim 5, wherein said TIMEK, TIMEN and GR are varied with a predetermined correlation therebetween. 
     
     
       7. The measuring apparatus in accordance with claim 1, further comprising alarm means for generating an alarm when said judging means detects that said actual distance between said vehicle and said object is less than said reference distance. 
     
     
       8. The measuring apparatus in accordance with claim 1, further comprising: collision predicting means for determining a possibility of collision, when said judging means detects that said actual distance between said vehicle and said object is less than said reference distance; and   alarm means for generating an alarm when said collision predicting means determines that possibility of collision exists.   
     
     
       9. A measuring apparatus comprising: measuring means for measuring an actual distance between a leading vehicle and a following vehicle traveling in generally same direction;   calculating means for calculating a reference distance based on traveling conditions of said leading vehicle and said following vehicle; and   judging means for judging whether said actual distance measured by said measuring means is less than said reference distance calculated by said calculating means,   wherein said calculating means comprises: first means for determining a personal space for a given driver in accordance with a speed of said following vehicle, said personal space being defined as a subjectively determined distance between said vehicle and said object at which said given driver is brought into a state of uneasiness;   second means for obtaining a free running distance, said free running distance representing a distance that said following vehicle travels until a braking operation is effected in said following vehicle;   third means for determining a braking distance, said braking distance representing a distance that said following vehicle travels until said following vehicle is stopped after said braking operation in said following vehicle is effected; and   fourth means for determining an acceleration change distance, said acceleration change distance representing a distance that said following vehicle travels due to a relative acceleration between said leading vehicle and said following vehicle,     whereby said calculating means calculates said reference distance based on said personal space obtained by said first means, said free running distance obtain by said second means, said braking distance obtained by said third means, and said acceleration change distance obtained by said fourth means, and wherein said calculating means calculates said reference distance using the formula:   VR·TIMEK--VRR·TIMEN+VRR.sup.2 /(2·GR)-αG·GA        where VR represents said vehicle speed of said following vehicle, TIMEK represents an uneasy factor expressed in terms of time and corresponds to said personal space VRR represents a relative speed between said leading vehicle and said following vehicle, TIMEN represents a response factor corresponding to a response time for effecting a following vehicle braking operation, GR represents a braking deceleration factor corresponding to a depressing strength of a braking pedal in said following vehicle braking operation, αG represents an acceleration of said leading vehicle, and GA represents a leading vehicle deceleration factor corresponding to a depressing strength of a braking pedal in a braking operation in said leading vehicle, felt by said driver of said following vehicle.   
     
     
       10. The measuring apparatus in accordance with claim 9, wherein said personal space said free running distance, and said braking distance are determined based on experiential data collected from a given driver's driving habits. 
     
     
       11. The measuring apparatus in accordance with claim 9, wherein travelling conditions of said leading vehicle and said following vehicle are measured as experiential data in relation to braking conditions of said following vehicle, and said reference distance is corrected based on said experiential data. 
     
     
       12. The measuring apparatus in accordance with claim 9, wherein said reference distance is manually adjustable. 
     
     
       13. The measuring apparatus in accordance with claim 9, wherein said TIMEK, TIMEN, GR and GA are variable to adjust said reference distance. 
     
     
       14. The measuring apparatus in accordance with claim 13, wherein said TIMEK, TIMEN, GR and GA are varied with a predetermined correlation therebetween. 
     
     
       15. The measuring apparatus in accordance with claim 9, further comprising alarm means for generating an alarm when said judging means detects that said actual distance between said leading vehicle and said following vehicle is less than said reference distance. 
     
     
       16. The measuring apparatus in accordance with claim 9, further comprising: collision predicting means for determining a possibility of collision between said leading and following vehicles, when said judging means detects that the actual distance between said leading vehicle and said following vehicle is less than said reference distance; and   alarm means for generating an alarm when said collision predicting means determines that the possibility of collision exists.   
     
     
       17. A measuring apparatus comprising: distance measuring means for measuring an actual distance between a vehicle and an object in front of said vehicle;   speed sensing means for measuring a speed of said vehicle;   personal data means for providing personal information corresponding to actual driving ability of a given driver of said vehicle;   calculating means, receiving data from said distance measuring means, said speed sensing means, and said personal data means, for calculating a reference distance with respect to said driving ability of said given driver of said vehicle; and   judging means for judging whether said actual distance measured by said distance measuring means is smaller than said reference distance calculated by said calculating means,   wherein said calculating means comprises: first means for determining a personal warning distance based on a first personal information datum provided from said personal data means and said speed of said vehicle measured by said speed sensing means;   second means for obtaining a free-running distance based on a second personal information datum provided from said personal data means and a relative speed between said vehicle and said object, which is calculated based on measurements measured by said distance measuring means and said speed sensing means; and   third means for obtaining a braking distance based on a third personal information datum provided from said personal data means and said relative speed between said vehicle and said object, calculated based on measurements measured by said distance measuring means and said speed sensing means, wherein said calculating means calculates said reference distance using the following formula:   VR·TIMEK-VRR·TIMEN+VRR.sup.2 /(2·GR)          where VR represents said speed of said vehicle, TIMEK represents said first personal information datum relating to said given driver's uneasiness corresponding to said personal warning distance, VRR represents said relative speed between said vehicle and said object, TIMEN represents said second personal information datum relating to a response time for a given driver's braking operation, and GR represents said third personal information datum relating to a strength with which a braking pedal is depressed by a given driver in a braking operation of said vehicle.   
     
     
       18. The measuring apparatus in accordance with claim 17, wherein said first, said second and said third personal information data are obtained as monitor data collected while a given driver is driving. 
     
     
       19. The measuring apparatus in accordance with claim 18, wherein said monitor data corresponding to said first, said second and said third personal information are data stored as map data in memory means. 
     
     
       20. A measuring apparatus comprising: distance measuring means for measuring an actual distance between a vehicle and an object in front of said vehicle;   speed sensing means for measuring a speed of said vehicle;   personal data means for providing personal information corresponding to actual driving ability of a given driver of said vehicle;   calculating means, receiving data from said distance measuring means, said speed sensing means, and said personal data means, for calculating a reference distance with respect to said driving ability of said given driver of said vehicle; and   judging means for judging whether said actual distance measured by said distance measuring means is smaller than said reference distance calculated by said calculating means,   wherein said calculating means comprises: first means for determining a personal warning distance based on a first personal information datum provided from said personal data means and said speed of said vehicle measured by said speed sensing means;   second means for obtaining a free-running distance based on a second personal information datum provided from said personal data means and a relative speed between said vehicle and said object, which is calculated based on measurements measured by said distance measuring means and said speed sensing means;   third means for obtaining a braking distance based on a third personal information datum provided from said personal data means and said relative speed between said vehicle and said object, calculated based on measurements measured by said distance measuring means and said speed sensing means; and   fourth means for determining an acceleration change distance based on a fourth personal information datum provided from said personal data means and a relative acceleration between said vehicle and said object, and     wherein said calculating means calculates said reference distance using the following formula:   VR·TIMEK-VRR·TIMEN+VRR.sup.2 /(2·GR)-αG·GA        where VR represents said speed of said vehicle TIMEK represents said first personal information datum relating to a given driver's uneasiness corresponding to said personal warning distance, VRR represents said relative speed between said vehicle and said object, TIMEN represents said second personal information datum relating to a response time for a given driver's braking operations, GR represents said third personal information datum relating to strength with which a braking pedal is depressed during a given driver's braking operation, αG represents an acceleration of said object, and GA represents said fourth personal information datum relating to deceleration of said object perceived a given driver of said vehicle.   
     
     
       21. A measuring apparatus comprising: distance measuring means for measuring an actual distance between a vehicle and an object positioned in front of said vehicle;   speed sensing means for measuring a speed of said vehicle;   relative speed calculating means for calculating a relative speed between said vehicle and said object based on data measured by said distance measuring means and said speed sensing means; and   alarm judging means, receiving data from said speed sensing means and said relative speed calculating means, for calculating a reference distance for preventing a collision between said vehicle and said object, said alarm judging means calculating said reference distance using the formula:   VR·TIMEK-VRR·TIMEN+VRR.sup.2 /(2·GR)        where VR represents said speed of said vehicle, TIMEK represents an uneasy factor relating to uneasiness of a given driver, VRR represents said relative speed between said vehicle and said object, TIMEN represents a response factor relating to a response time for a given driver's braking operation, and GR represents a deceleration factor relating to a strength with which a braking pedal is depressed in a given driver's braking operation.   
     
     
       22. The measuring apparatus in accordance with claim 21, wherein said alarm judging means judges whether said actual distance measured by said distance measuring means is smaller than said reference distance. 
     
     
       23. The measuring apparatus in accordance with claim 21, further comprising alarm sensitivity setting means for allowing each driver to manually adjust said uneasy, response, and deceleration factors. 
     
     
       24. A measuring apparatus comprising: distance measuring means for measuring an actual distance between a vehicle and an object positioned in front of said vehicle;   speed sensing means for measuring a speed of said vehicle;   relative speed calculating means for calculating a relative speed between said vehicle and said object based on measurements measured by said distance measuring means and said speed sensing means;   relative acceleration calculating means for calculating a relative acceleration between said vehicle and said object; and   alarm judging means, receiving data from said speed sensing means, said relative speed calculating means, and said relative acceleration calculating means, for calculating a reference distance for preventing a collision between said vehicle and said object, said alarm judging means calculating said reference distance using the formula:   VR·TIMEK-VRR·TIMEN+VRR.sup.2 /(2·GR)-αG·GA        where VR represents said speed of said vehicle, TIMEK represents an uneasy factor relating to uneasiness of a given driver, VRR represents said relative speed between said vehicle and said object, TIMEN represents a response factor relating to a response time for a given driver's braking operation, GR represents a deceleration factor relating to a strength with which a braking pedal is depressed in a given driver's braking operation, αG represents said relative acceleration between said vehicle and said object, and GA represents a preceding object deceleration factor perceived by a given driver of said vehicle.   
     
     
       25. The measuring apparatus in accordance with claim 24, wherein said alarm judging means determines whether said actual distance measured by said distance measuring means is less than said reference distance. 
     
     
       26. The measuring apparatus in accordance with claim 24, further comprising alarm sensitivity setting means for allowing each driver to manually adjust said uneasy, response, and deceleration factors.